With the development of the flat display panel industry, the requirements of the resolution are getting higher. A display device with a high PPI (pixels per inch, pixel number in per inch) has become a standard equipment of a digital electronic product.
The conventional method of manufacturing a high PPI display device includes the following steps: manufacturing a TFT substrate; manufacturing an emission layer (forming liquid crystal cells or depositing OLED, etc.); bonding (connecting an electric module to a display device); and assembling a product. However, as the resolution is increased, the bonding terminals of the electric module such as IC (integrated circuit), FPC (flexible printed circuit) are increased. For example, the resolution of the mainstream display device is 1920×1080, the TFT substrate need to have 1080 bonding terminals to connect the IC/FPC, so more bonding terminals in the same area need to be manufactured. Therefore, the area of the bonding terminal, the distance between the bonding terminals will be decreased. Currently, the electrical connection between the display device and the IC/FPC is applied ACF (anisotropic conductive film) under the condition of high temperature and high pressure.
However, with the development of flexible and high-resolution panels, the integration of terminals is getting higher, and the spacing between terminals is getting smaller. Refer to FIG. 1, if using the conventional bonding method to connect the bonding between the display device and the IC/FPC, the bonding shift will happen to cause the problem of short circuit or poor contact, and the product yield will be decreased.